Thin shallow spherical shell theory is used to derive the general influence function, owing to uniform and/or discrete (actuators) loads, for a thin shallow meniscus-shaped mirror of uniform thickness with a central hole and supported at discrete points. Small elastic deformations are considered. No symmetry on the load distribution constrains the model. Explicit analytical expressions of the s...

The onset of plastic yielding in a spherical shell loaded by a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the critical normal load, critical interference, and critical contact area, at the onset of plastic yielding, is investigated and the location where plastic yielding first occurs is determined. A universal dimensio...

We investigate the influence of the curvature of the Earth on a proposed atmospheric-correction scheme for the Sea-Viewing Wide-Field-of-View Sensor (SeaWiFS) by simulating the radiance exiting the top of a spherical-shell atmosphere and inserting the result into the proposed correction algorithm. The error in the derived water-leaving reflectance suggests that the effects of the curvature are ...

The boundary value problem (BVP) for a class of nonlinear ordinary differential equations is examined. It can be used to describe the eversion problem for a spherical shell composed of a class of transversely isotropic incompressible Mooney-Rivlin materials. The solutions of the nonlinear equation describing the relation among deformed thickness, initial thickness and material parameters of the...

This paper presents a study on nonlinear asymmetric vibrations in shallow spherical caps under pressure loading. The Novozhilov’s shell theory is used for modeling the structural strains. A reduced-order model developed through Rayleigh–Ritz method and Lagrange equations. equations of motion are numerically integrated using an implicit solver. bifurcation scenario addressed by varying external ...

This paper presents a follow-up study of previous work that deals with the free vibration moderately thin isotropic shallow shells under general edge conditions. The same semi-analytical method is used in this for identical shape and degree curvature doubly curved geometry, accurate natural frequencies are tabulated wide range shell Emphasis made, however, to present frequency parameters very t...

The elastic buckling of shell structures such as spherical shells subject to external pressure and cylindrical shells loaded in axial compression is highly sensitive to imperfections and often catastrophic. Recent studies of spherical shells have provided accurate quantitative results for the relation between the buckling pressure and the amplitude and shape of geometric imperfections and, addi...

Through acoustic scattering theory we derive the mass density and bulk modulus of a spherical shell that can eliminate scattering from an arbitrary object in the interior of the shell--in other words, a 3D acoustic cloaking shell. Calculations confirm that the pressure and velocity fields are smoothly bent and excluded from the central region as for previously reported electromagnetic cloaking ...

Snap-through buckling behaviour of rigid vinyl polyethylene shallow spherical shells, undergoing large displacements, subjected to static ring loads is investigated by using finite difference and the Newton-Raphson Method. The load-deflection diagrams corresponding various values thickness, depth diameter shell with simply supported clamped edges are sketched compared. accuracy used algorithm p...